<script lang="ts" setup>
import { onMounted, onUnmounted, ref } from "vue";
import { CarouselItem } from "../../types/carousel";
defineOptions({
  name: "XtxCarousel",
});
// 指定 props 默认值的时候，可以在这儿 const {} = defineProps()，实现性语法，需要在 vite.config.ts 中开启 reactivityTransform
// 单独写要 const {} = toRefs(props)，后面使用默认值的时候要加 .value
const {
  slides,
  autoPlay = false,
  duration = 3000,
} = defineProps<{
  slides: CarouselItem[];
  autoPlay: boolean;
  duration?: number;
}>();

const active = ref(0);
const onPrev = () => {
  active.value--;
  if (active.value < 0) {
    active.value = slides.length - 1;
  }
};
const onNext = () => {
  active.value++;
  // if (active.value >= slides.length) {
  if (active.value > slides.length - 1) {
    active.value = 0;
  }
};

let timer: number = -1;
onUnmounted(() => {
  clearInterval(timer);
});
// 抽离播放的方法
const play = () => {
  if (!autoPlay) return
  // 开启定时器之前，最好先清一下之前的，好习惯！
  clearInterval(timer);
  // 模块化环境编写代码时，定时器会被识别为 Node 中的语法
  timer = window.setInterval(() => {
    onNext();
  }, duration);
};
onMounted(() => {
  play();
});
const stop = () => {
  clearInterval(timer);
};
</script>

<template>
  <div class="xtx-carousel" @mouseenter="stop" @mouseleave="play">
    <ul class="carousel-body">
      <li class="carousel-item" v-for="(item, index) in slides" :key="item.id" :class="{ fade: active === index }">
        <img :src="item.imgUrl" alt="" />
      </li>
    </ul>
    <a href="javascript:;" class="carousel-btn prev" @click="onPrev"><i class="iconfont icon-angle-left"></i></a>
    <a href="javascript:;" class="carousel-btn next" @click="onNext"><i class="iconfont icon-angle-right"></i></a>
    <div class="carousel-indicator">
      <span :class="{ active: active === index }" v-for="(item, index) in slides" :key="item.id" @mouseenter="active = index"></span>
    </div>
  </div>
</template>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 350px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 50%;
      transform: translateY(-50%);
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>
